Installing Clang for QDoc

QDoc uses Clang when parsing C++ files as well as function signatures in \fn commands. Clang is part of the LLVM Compiler Infrastructure Project. If you're going to build QDoc from source, you must install Clang 17.0 or later.

You can get Clang through various channels:

  • Qt provides the prebuilt Clang packages that are used for the Qt binaries in the online installer. These let you link LLVM/Clang libraries statically, but only support Release builds on Windows.
  • Linux distributions often provide a package called libclang-dev or libclang-devel. Qt's build system instructs CMake to look for ClangConfig.cmake, so make sure you install the package that provides this file if you want to build QDoc. Running QDoc requires only libclang.
  • On macOS, you can also use Homebrew's llvm formula.

Note: the prebuilt binaries from cannot be used, as they miss certain components required by QDoc.

If you install Clang in a custom location you need to tell CMake where to find it. This can be done by specifying your LLVM installation path using the LLVM_INSTALL_DIR environment variable when configuring Qt. Alternatively, you can add the installation path to the CMAKE_PREFIX_PATH CMake cache variable.

© 2024 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.